Process for reforming and polymerizing hydrocarbons



Mrch 31, 1942. P, SUBKQW 2,277,938

PROCESS FOR REFORMING AND POLYMERIZING HYDROCARBONS Original Filed Aug. l2, 1935 2 Sheets-Sheet 1 l (Coo/er INI/ENTR Philip bkOW Afro EY March 3 1,r 1942. P. SUBKOW 2,277,938

v PROCESS, FOR REFORMING AND EOLYMERIZING HYDROCARBONS I original Filed Aug. 12, 19:55 2 sheets-sheet 2 Separaor\ `Patented Mar. 31 1942 UNITED STATES PATENT .OFFICE Pnocnss Foa nEFoaMING AND PoLY- MERIZING nYDRocARBoNs -Philip Subkow, West Los Angeles, Calif., assignor to Union Oil Company of California, Los

Angeles, Calif., a corporation of California Original application August 12, 1935, Serial No. 35,702. Divided and this application July 12, 1938, Serial No. 218,777

4 claims. (ci. 19e-9)- ticularly those which are normally gaseous at atmospheric temperatures and pressures, and known as polymerization or synthesis and processes for obtaining improved anti-knock qualities by molecular rearrangement, known as isomerization."

The conventional process for reforming gasoline consists in subjecting hydrocarbons in the gasoline range, preferably in vaporous form, to high temperatures, under which conditions the gasoline is converted from one having low antiknock properties to one having high anti-knock properties. The .gasoline is then separated from the xed gases and normally gaseous hydrocarbons to form a stabilized and reformed gasoline. This process for the formation of high iso-octane number material is visualized as proceeding through cracking, dehydrogenating and isomerizing reactions which yield as an intermediate or by-product, low molecular weight olenic fractions and chemical radicals with unsatisfied valences called residuals. In conventional'reforming operations there is no attempt to control the subsequent polymerization of these materials to retain and conserve those desirable anti-knock characteristics and to polymerize the gaseous residuals to liquid hydrocarbons of high anti-knock value. The process of this invention provides for controlled polymerization and conservation of `these residuals and olefins, particularly those of the ethylenic type, in the reaction zones, thus favoring continued decomposition of the petroleum hydrocarbons and increased yield of high octane material over that resulting from a simple reforming operation. A reformed gasoline containing increased percentages of polymer gasoline of high octane value results.

The reactions here generically termed polymerization" include alkylation reactions wherein saturated hydrocarbons combine with unsaturated hydrocarbons to form high molecular weight branched chain hydrocarbons or alkylation reactions between aromatics and unsaturated low molecular weight hydrocarbons such as ethylene, propane or butene, or straight polymerization reactions wherein olens such as mono or diolefins are polymerized to higher molecular weight polymers. Isomerization, although not strictly a polymerization reaction in the sense that higher molecular weight bodies are formed, is included within this term since it occurs along with such polymerization reactions. The term polymerization as here used is intended to embrace these types of reactions for building higher molecular weight bodies by reaction of lower molecular weight hydrocarbons.A The gasoline produced by this process is termed polymer gas.

oline, and when produced as a mixture with reformed gasoline it is here termed reformed and polymer gasoline.

converted into polymerized materials, and ay blend of reformed and polymer gasoline is formed directly in the process. Broadly stated, the invention consists in reforming liquid hydrocarbons, and particularly hydrocarbons in the gasoline range, to produce hydrocarbons having boiling points in the gasoline range and vapors containing hydrocarbons of five or less carbon atoms, which vapors are polymerized, separately if desired, but'preferably in the presence of the gasoline fractions produced by the reforming operation. t p

The invention also contemplates the addition `of hydrocarbons having five or less carbon atoms to the gasoline being polymerized to increase the concentration of these hydrocarbons. .t

Normally gaseous hydrocarbons such as .pro-

pane, butane, propylene or butylene may be polyv- .merized Instead of using the hydrocarbons having four or less carbon atoms, stabilized natural gasoline containing these fractions may be employed. It is preferred, however, to use hydrocarbons of the unsaturated type. Sources of such gases are processes in which gas oil and/or fuel oil are cracked at temperatures below 1000 F.,- that is, in the neighborhood'of S50-950 F.

, The reforming operation, which is at leastI partially a combined cracking, dehydrogenating and isomerizing operation, may be aided by choice of conditions of temperature and pressure' .and rate of feed and by selection of catalysts. In

general, high temperatures, short time, and modr range from 650-1850 F., but the range from 850-1200 F. is preferred.. Pressures ranging from atmospheric to 1500 lbs. may be used, but 10W pressures, as for instance, in the neighborhood of 5-30 atmospheres, are to be preferred. Reforming catalysts for the above process which 4have been found useful for this purpose are:

M @tala-Nickel, palladium, platinum, copper, co-

balt, iron, zinc, titanium, aluminum, tungsten, molybdenum, thorium;

`Suljdes.-Cobalt, iron, zinc, nickel, manganese,

tungsten;

Oxides-Alkali metals such as calcium, magnesium, barium, aluminum, chromium, zinc, manganese, silica;

Hydroxz'des.-Chromium, alkali metal;

Acids.-Molybdic, tungstic, chromic, phosphoric,

arsenious, silica, boric;

Salts.-Alummates, chromates, tungstates, vanadates, uranates, phosphates, of the alkali earth metals such as calcium; and the phosphates, chromates and vanadates of aluminum, chromium or zinc; phosphates of molybdenum, tungsten; ammonium molybdate, aluminum sulfate; adsorbents like fullers earth, bentonite;

Adsorbent charcoal or other adsorbent carbons;

Halz'des such as aluminum chloride, iron chloride,

aluminum bromide and iron bromide.

When hydrocarbon fractions having a boiling range up to about 60G-650 F. are passed over these catalysts at temperatures from 6621832 F. a reforming reaction occurs. In producing gasoline containing oleiinie materials temperatures of about 850-1050J F. may be employed. Higher temperatures in the neighborhood of 1380-1830" F. favor aromatic formation. The salts and 0X- ides of the diilcultly reducible metals, as for instance, the alkali metals such as calcium, magnesium, barium, require in general higher ternperatures for the formation of oleins, i. e. temperatures in the neighborhood of 1020-1380 F. The gases resulting may then be reacted in the presence of a polymerizingcatalyst.

Catalysts which have been found to aid poly- -f formed when precipitated on a carrier or fused with a. carrier and ground into a fine state. The clays such as bentonite and fullers earth are best used in their activated states, thus fullers earth is used in the acid treated state, in which state their adsorptive activity is best brought out. Methods of increasing the adsorptive activity of clays and adsorbent carbon are well known in the adsorption art.

In using catalysts to be carried in the stream of s gases, the catalyst, if it is boron fluoride, may be state at low temperature.

' contact mass in the reaction zone and the vapors merization are termed polymerizing catalysts."

phate, aluminum sulfate in solid form, adsorbent o clays like bentonite, graphite, charcoal, copper alkali metal salts (especially oxygen-containing salts), phosphates, borates, antimonates, boron trifluoride, either alone or as a double compoundwith ethylene in the form of ethylene fluoborio acid,- cadmium phosphate, and siliceous earths, tin, zinc, aluminum, chromium, silicon, lead or alloys of these metals.

In using the reforming and polymerizing catalysts, one skilled m the art win understand that the conventional methods of preparing catalystsy of this nature are to be followed. Thus, the metals are best used when in nely divided form, and better when supported on carriers. Forexample, the metal might be formed by reducing the oxide of metal absorbed upon a carrier such as charcoal or silica gel in a stream of hydrogen. These methods are well known and conventional in the catalytic art. The salts or acids are best passed through the body of catalyst.

The reactions which have been termed poly- 1 merization reaction, and reforming reaction are parallel reactions. These reactions are generally reversible, the reaction in one direction being a polymerization reaction, and the reaction in the other direction being a reforming reaction. Consequently, in the polymerization operation and in the reforming operation, all reactions may occur. In general, the polymerization reactions are favored by lower temperatures, while the reforming reactions are favored by higher temperatures, the temperatures chosen should be those at which the desired reaction predominates. The temperature will also vary with the feed stock, particularly upon its boiling range and the kchemical type of the feed stock and with the pressure. An additional factor is time. The polymerization reactions and decomposition reactions may proceed further by allowing a longer time of contact with the' catalyst. Care must be taken to prevent the reforming reaction from going tooA far, thus forming light, undesirable fractions, or from allowing the polymerization reaction to form undesirable heavy bodies by too long a polymerization contact time.

Various catalysts promote one or the other reactions favorably, under certain temperature conditions. The temperatures and pressures herein disclosed are merely illustrative and are those at which the various reactions predominate, but the opposite reaction, whether it be reforming or polymerization, also occurs. The temperatures are merely illustrative -and are for feed stocks as herein described, and for pressures from atmospheric to 5000 lbs.

Thus, with metal catalysts, tin, zinc, copper, aluminum, chromium, silicon, lead and nickel favor polymerization reactions in the temperature range between 350 and '700 F. Nickel favors the reaction in the lower ofthe said range, that is, around 350-355 F. These materials favor the reforming operation at higher temperatures. Iron and nickel favor the reforming operation above about 390 F. and in general, iron, nickel, copper, cobalt, zinc, aluminum, chromium favor the reforming operation at temperature ranges above 932 F.

It will be seen that certain of the materials here recited, for example, both zinc and nickel catalyze both reactions, but at lower temperatures, zinc in the range between 350-700 F., and nickel in the range between 35S-390 F. favor the polymerization reaction, while the reforming reaction is favored at temperatures above 930 F. In y choosing temperatures for polymerization and reforming, using metal catalysts of the nature aar/,oss

shown above, it is preferable that polymerization reactions be carried out at lower temperatures here indicated, and the reforming operations at the higher temperatures, however, by applying higher pressures as hereinafter described, the reaction temperatures are brought closer together and polymerization and reforming may occur together at the same temperature.

Catalytic oxides used for these reactions, such as aluminum oxide either alone or combined with silica in the form of aluminum silicates, for instance, oridinor fullers earth, favor polymerization in the temperature range between 570 and 750 F. Preferably, aluminum oxide should be used in the neighborhood offrom 640 to 700 F.

Lime and otherv alkali earths or oxides or carbonates favor polymerization in the range between 660 F. and 840 F. Magnesium and beryl' lium oxides favor polymerization reactions in the upper part of said range around 840 F. to 930 F. Aluminum chloride and boron trifluoride are Very active at temperatures from 32 F. to 300 or 390 F. Magnesium oxide, lime and silica, such as silica gel, can be used in reforming reactions in temperature ranges above 930-1290'F. Aluminum oxide or aluminum silicate such as fullers earth or fioridin or other forms will favor reforming above 750 F. 'I'hus in using aluminum oxide, either alone or in the form of silicate, the temperature ranges should be adjusted depending on the form of the reaction which is to be favored. In operating in the upper ranges around '750 F. aluminum oxide will have a favorable influence on both reactions, aiding in the decomposition in the higher molecular weight liquid hydrocarbons, and aiding in the lower molecular weight gaseous hydrocarbons. The temperature range should be chosen to form a balance between the two.

IOf the salts or adsorbents which accelerate polymerization reaction, the alkli metal carbonates, phosphates and borates are active in the neighborhood of 750-930 F.; bentonite is active from 660840 F.; phosphoric acid is active from S50-475 F. Absorbent charcoals and carbons favor the polymerization reaction at around 750 F. r Above these temperatures, and particularly at substantially higher temperatures reforming is favored by these catalysts. Calcium aluminate, ammonium molybdate favor the reforming operations 'at temperatures of 930-1290 F. and higher. Aluminum sulfate and phosphoric acid are active in reforming reactions above 660 F. and very active above 930 F.

Mixed catalysts composed of mixtures of any one or more of the above reforming catalysts, and any one or more 'of the above polymerizing catalysts, which are active, i. e. promote and accelerate the reforming and polymerizing operation in the neighborhood of 700-930 F. will permit of the joint and favorable reactions'of reforming and polymerization when operated at temperatures between about 700-930 F. at pressures of about r l5-1500 lbs.

Higher pressures favor the polymerization reaction and therefore, by the amplification of pressure, the tolerable temperature for polymerization is increased; At the same time pressure tends todecrease the reforming operation, and the two operationsmay be brought closer together by theapplication of pressure. By choosing a temperature intermediate the preferred reforming and polymerization reaction temperature at atmospheric pressure, and applying high pressure-inthe neighborhood of 100G-5000 lbs. the

same catalyst may be used for both reactions. It may be chosen to use a catalyst or catalyst mixtures whose temperature at which they accelerate 'the reforming operation, and the temperature at which they accelerate the polymerization operation, do not lie far apart. Thus, for` instance, one may choose catalysts which are active, i. e. promote or accelerate, in reforming at temperatures in the neighborhood @f 8401060 F., and choose catalysts which are active in, i. e. promote or accelerate, the polymerizing-reaction at temperatures ranging from about 570-840 F.

, at pressures ranging as low as atmospheric.

'The liquid gases may be washed with alkali to' are not easily poisoned by the sulfur and sulfur bodies present in the charging stocks here used. Metals: cobalt, iron, zinc; sulfides of cobalt, iron, zinc, nickel, manganese, tungsten; oxides of chromium, zinc, manganese, aluminium; chromium hydroxide; molybdic, tungstic, chromic, phosphoric, arsenious, silicio, boric acids; phosphates of alkali metals, molybdenum, tungsten; am-

monium molybdate,. aluminum silicate, fullers earth.

Water and oxygen and traces of alkali poison aluminum oxide and fullers` earth catalysts. Small percentages of moisture in such catalysts as hereinafter described may be tolerated. Oxygen also poisons aluminum oxide, fullers earth,

' tral and dehydrated. It is preferred that the mixture be neutral or acid, and free of alkaline material.- It is best that the catalyst be substantially free from water, dehydrated by heating, al/

propylene over the above fullers earth type catalysts as previously disclosed at ordinary temperatures from about 20G-400 F. the alkyl chloride may be introduced either in vapor' form as produced by the chlorinating reaction, or first-condensed, and then introduced in liquid form. `'I'he amount of alkyl chloride required varies from one-tenth to one percent, preferably to about one-half percent of the reaction vapors.

The ycatalysts here employed may be used in the reforming or polymerizing processes either as a catalyst body or as a mixture'with incoming feed. In using the catalyst as a catalyst body, the reaction zone in the tube or chamber is charged with the solid catalyst and the reaction vapors are passed through the body of the catalyst. It is possible, however, to use the catalyst as a slurry with the incoming feed, in which case the reaction zones are empty except for the reaction mixture. When the vaporized hydrocarbons carrying the catalyst ground fine in suspension pass through the reaction zone, the high velocity of the vapors and the ne particle size of the catalyst prevent sedimentation of the cata.- lyst in the tubes or chambers.

In carrying out the process of this invention the following principles may act as a guide. The feed of liquid fractions is one preferably having an end point not in excess of 650 F. Usually a heavy gasoline fraction boiling between 300-500 F. -will prove satisfactory. The reforming, cracking or dehydrogenation is best carried out at a temperature plane higher than that at which the polymerization reaction is carried out. It is desirable also to control these reactions so that they do not proceed to the ultimate stage of carbon, hydrogen and methane formation or to the production of high boiling fractions in the fuel oil range. It therefore will be desirable in one form of this invention to use relatively high temperatures and short times of contact in the reforming zone, and to cool the reaction products produced by the dehydrogenating and cracking reactions before passing them to the polymerization reaction zone. 'I'he yield of polymerization products may be increased by adding to the reaction mixture rom an extraneous source hydrocarbon materials of five or less carbon atoms. The polymerizing reaction including addition of unsaturates to unsaturates and alkylation in poly-molecular reaction is favorably influenced by increasing the concentration of the reactants. This may be accomplished by increasingthe pressure, and also by adding materials undergoing polymerizing reaction to the reformed vapors. These may be cracking still gases, or liquid gas from a gasoline stabilizer tower.

It is desirable to have present unsaturated hydrocarbons such as butenes, propenes and ethylene, the gases may be obtained fromv the cracking of gas oil or fuel oil at temperatures from 850-l000 F. and preferably, from 90B-'950 F. The gases are those produced after the cracked gasoline has been removed. Other processes for producing these unsaturates may be employed to produce the unsaturated normally gasl in passing through the polymerization stage. The

difficulty of compressing hot vapors makes this step practically difficult. It is, therefore, desirable to compress only the cold feed and to operate the whole system under the desired high p ressure for the polymerizing reaction. The use of catalysts permits the use of lower pressures for thel polymerizing reaction and lower temperatures for the reforming reaction than would be possible without the catalyst.

While the processes of reforming and polyl merization are two distinct processes which may be separated the one from the other by careful choice of conditions and catalysts by control of conditions, as previously described, the two processes may be interwoven.

In operating a combination of reforming and polymerization such as, for example, those shown in Figures 1, 2, 3, and 5, where saturated normally gaseous hydrocarbons are introducedv into the reforming zone, this reforming may be operated at a relatively high temperature to form larger amounts of unsaturated normally gaseous hydrocarbons in the vapor mixture passing to the polymerization stage. In such a process an active dehydrogenating or reforming catalyst may be employed. The temperatures to be employed may be in the upper portion of the range suggested for the reforming catalyst. Another procedure to be followed in this connection is to carry the reforming on at relatively high temperatures to produce large amounts of gas by extensive cracking of the feed stock. Thus, for instance, in operating on a charging stock composed of crude gasoline of from 15G-500o F. end point, the cracking may be carried on to produce large gas yields in excess of 40G-500 cu. ft. per barrel of charging stock. These gases, together with any added gas may be passed to the polymerization stage. In this connection the gasoline fractions may be rst removed and the lighter gases polymerized or the polymerization may be carried on in the presence of the reformed gasoline fractions.

The cracking and dehydrogenating processes of reforming are reversible reactions, and concomitant with them occur polymerizing and hydrogenating reactions. The unsaturated bodies formed as a result of the cracking and dehydrogenation are extremely active and tend to combine with each other. The light unsaturated gases tend to polymerize with themselves and with the unsaturated higher molecular weight bodies present in the reaction zone. It is therefore possible to combine the reforming and polymerizing processes .and to carry on the polymei-ization of the lighter fractions (flve carbon, and particularly four carbon and. lower) in the presence of the hydrocarbons within the gasoline range formed as a result of the reforming operation. By such a combined process, the low molecular weight olefinic products of the reforming processes are continuously and progressively removed by polymerization from the reaction zone as they are formed, thus favoring continued reforming of the petroleum hydrocarbons and an increased yield of high octane material vover that resulting from a simple reforming operation. The lower molecular weight unsaturated hydrocarbons, particularly those of ve carbon atoms and less are polymerized with themselves and are also polymerized by addition of the higher molecular weight liquid hydrocarbons of six carbon atoms andV more formed in the reforming reaction, or present in the hydrocarbon material forming the charge to the operation. y

If desired, instead of using a mixture of catalysts, the catalytic zones may be separated and the reaction mixture passed separately or alternately over a dehydrogenation and polymerization catalyst. This may be accomplished by passing the mixture through a series of tubes of the nature of cracking tubes connected together by return bends and the tubes filled alternately with a dehydrogenation and a polymerization catalyst in a number of runs so that the mixture is reformed and polymerized in repeated passages over the catalyst. The tubes may be placed in a furnace and the temperature and pressure may be uniform throughout the tubes or the tubes may be placed in reaction zones of different temperatures, the reforming tubes being at higher temperatures than the polymerization tubes. The

reaction mixture is then heated and cooled, 'first heated to the reforming temperature in the reforming tubes,` then cooled to a lower polymerizing temperature in the polymerization zone. If desired, temperature alone may be used to produce the desired reforming and polymerizatlon Without using catalysts in the tubes.

While catalytic operations are preferred, certain of the advantages of this operation are preserved in non-catalytic processes thus either the reforming or polymerizing reaction or both may be operated without the aid of catalysts to obtain a great number of the advantagesof the opera- Another arrangement which may be used is to carry out the process in a heated chamber through which are passed cooling tubes. Cracking and dehydrogenating catalysts may be deposited on the warm walls of the chamber,V and polymerizing action which only affects those unsaturates which are most readily polymerized and leaves the others to contribute their high antidetonating characteristics to the fuel.

The process of polymerization and also of reforming results in a product which is composed of a polymer and reformed gasoline fraction of high octane and having an end point of from 30D-400 F. depending on operations, a heavy gasoline-kerosene fraction having anA end point of about 50G-550 F'. and a heavy portion. The heavier fractions called "heavy gasoline-kerosene is recycled. While the figures describe the total return, it will be understood that only a portion may be returned and the remaining portion sent to storage or re-run on blending stock with the polymer and reformed gasoline.

It is therefore an object of this invention to subject kerosene and gasoline and heavier petroleum fractions to a reforming operation in the presence of a reforming catalyst.

It is a further object of this invention vto form a reformed and polymer gasoline by subjecting gasoline, kerosene and heavier hydrocarbons to a reforming process and tosubject light hydrocarbons to a polymerizing reactionv to form a polymer gasoline, and to combine and rectify the two to produce a reformed and polymer gasoline.

It "s another object of this invention to subject gasoline and kerosene and heavier petroleum fractions to a reforming operation in the presence 'of a catalyst which will aid the polymerization of the lighter hydrocarbon fractions, and

particularly, those which are normally gaseous in the reforming operation. Y

A It is a further object of this invention to subject gasoline and kerosene and heavier petroleum` fractions in the presence of a normally gaseousl fractions to a reforming operation and then' to subject the product of the reforming operation to a polymerizing reaction, preferably in the presence of a polymerization catalyst.

It is a further object of this invention to subject gasoline and kerosene and heavier petroleum fractions to a reforming operation, and then to subject the product of the reforming operation in the presence of added normally gaseous hydrocarbons to a polymerization reaction, preferably in the presence of a polymerization catalyst.

It is a further object of this invention to subject gasoline and kerosene and heavier petroleum fractions to a reforming and polymerization reaction in the presence of a reforming and polymerization catalyst under such high pressure conditions and such conditions of temperature that the polymerization and reforming operations are both aided by the presence of the polymerization and reforming catalysts.-

It is a further object of this invention to subject gasoline and kerosene and heavier petroleum fractions to a reforming operation and subsequently to a polymerization operation under such conditions of temperature and pressure that the reforming operation is carried out at a higher temperature than the polymerization operation wherein the reformed gasoline composed of gasoline and kerosene'fractions, and containing normally gaseous hydrocarbons are subject to a lower temperature for polymerization of the polymerizable hydrocarbons at that temperature and pressure.

This invention will be better understood by reference to the subjoined figures'` in which:

Figure 1 is a ow sheet showing the polymerization and reforming reactions and providing for withdrawal and the addition of a catalyst at an intermediate point in the reaction;

Figure 2 shows a stage reforming and polymerization reaction in which a promoter is added to the reaction undergoing polymerization;

Figure 3 shows a stage polymerization and reforming reaction wherein provision is made for the control of temperature in the polymerization reaction;

Figure 4 shows a combined polymerization and reforming operation; A v

Figure 5 shows a design and flow sheet of a combined polymerization and reforming operation and a furnace structure for the control of temperature in the various coils of the furnace;

Figure 6 shows a simultaneous polymerization and reforming operation wherein the polymeriza- .tion and reforming operations are carried on separately, and the products are combined and treated together.

Figure 1 represents a schematic flow sheet of a combined reforming and polymerization process in which the reforming is primarily conducted in one zone at relatively higher temperature and polymerization in another zone of relatively lower temperature. In Figure 1 gasoline, kerosene, or gasoil fractions having end points under 60o-650 F. to be reformed are fed through line i by pump 2 through valve 3 and line 4 into the reforming lcoil l in furnace 8. The reforming catalyst may be added .before passage to the heating coil through line 5 controlled by Valve 6.. The mechanism for the addition of thesolid catalyst tothe oil stream is shown schematically as indicated. Mechanisms for the addition of solid material to liquid being well known in the chemical engineering art. The reforming catalyst may be one of the previously mentioned catalysts or may be a mixture of reforming and polymerization catalysts. The temperature of the reforming operation will be chosen to correspond with the catalyst used in accordance with the principles hereinabove discussed.

The reforming stream containing the catalysts may be treated in one of two ways. If the prior reforming operation was made in the presence of a catalyst or catalyst mixtures different from those which it is desired to have present in the polymerization zone, the stream is by-passed by closing valve I4 and opening valves I0 and I6. The stream of catalyst and oil vapor is then passed through line 9 and meets oil residuum such as fuel oil entering at II to act as a dousing medium to wash out entrained catalysts and sepadjusting the valves 28a in lines 28 and valved line 29' and valves 3Ia and 32a in line 3| so that the flow will be downward through the reactor and into fractionator 33. If the catalyst contact mass is used, it may be desirable to flow the vapors upwardly through the reactor and in which arate the vapors from the dousing medium in the separator I2. The temperature maintained in the separator is about 500 F. to insure the vaporization of the gasoline fractions. ture of oil and catalyst is removed through valve controlled line I3, and the vapors of gasoline and lighter fractions including the hydrocarbons of four and less carbon atoms, pass through line I5 and Valve I6 into line 9. However, if it is desired that the catalyst present in the reforming coil 1 and catalysts entrained in the vapors passing therethrough be also present in the polymerization zone, valves I0 and I6 remain closed and valve I4 is open. In the event the operation in chamber I2 is carried out, additional catalysts may be added through line` I1 or provided as catalytic mass in the reactor chamber 29. It may be found desirable to add fresh catalysts to the reaction mixture. Also, in the event that the operation in chamber I2 is not carried out, the reaction mixture passes through line 9 in order to increase the concentration of active catalysts in the reaction mixture.

The reforming operation may be carried out with the omission of catalyst introduction through 5, and the entire reformed mixture may be passed either through I4 or by-passed to I2 and the separated gasoline sent to reactor chamber 29 in the same manner as previously demixtures of these hydrocarbons with the saturi ated hydrocarbons of four or less carbon atoms. The mixture is formed in line 9. In the event The mixthat the cooling operation in chamber I2 and the cooling effected by the addition of the liquid material through line I8 and vaporization of this material has reduced the temperature below the chosen reaction temperatura'the mixture may be by-passed through4 line 23 and reheating coil 25 in furnace 8 by the proper manipulation of valves 2 case by proper manipulation of the valves 29a, 28a, 3Ia and 32a, the flow may be properly directed. Gasoline thus formed will result from the reforming reactions operating on the charge to coils 1 and on polymerization of the reformed vapors and gases. i

The reformed and polymer gasoline then passes through fractionator 33 containing the usual reflux cooler 42 which may be either internal or external. The heavy fraction, containing the suspended catalyst if this is combined in the vapors is removed from the tower through line 34 controlled by valve 35. The heavy gasoline fraction is removed through line 36, pump 31 for recycling to the reforming operation via line I9 or is removed from the system partially or totally. The reformed and polymer gasoline is removed through side stream take-off 38 into `tank 39, passed by pump 40 through heater 4I compressor 43aand line 44 into the stabilizer 46.

The gasolines and gas are separated into a stabilized gasoline removed through line 5I, valve 52, and cooler 53 and the liquid gas fraction containing butanes, butylenes, propanes, propylenes, some ethane and ethylenes in liquid form pass into tank 56 and circulate by pump 51 through line 20 as previously described. Heat is supplied to the bottom of the tower by circulation from a lower tray through line 41, heater 49, and returned through line 50. The uncondensed and fixed gases are removed through line 54,' controlled by valve 55.

The conditions to be maintained in heater 1 and in the reactor 29 are those previously described and must be adjusted for the stock and catalyst employed as will be well understood in the art.

In carrying out the process shown in Figure 1, any one of the catalysts here described may be employed, but the flow will be explained using one of the catalysts merely to illustrate the principle of carrying out the reaction.

It will be understood that the other catalysts may be used with the proper control of temperature and pressure according to the principles hereinabove fully described.

A kerosene fraction having an end point of about 550 F. is .passed through line 3 and is intimately incorporated to form a slurry with molybdic acid, molybdenum sulfide, or calcium aluminate, and is heated to a temperature of about 930 to 12.90 F. in coil 1. The mixture is then passed through line 9 into chamber I2 in which the catalyst and the oil are withdrawn and the vapors at a temperature of about 450 F. are withdrawn through line I5. Material is added through line I8 and the mixture at a temperature of about 350 to 400 F. is introduced into chamber 29 which is charged with a phosphoric acid catalyst in the form of orthophosphoric acid deposited upon a fullers earth base. The pressure maintained in the coil 1 and the chamber 29 is about 500 to 1000 lbs.

Figure 2 shows an operation of reforming and polymerization wherein the reactions occur in the presence of an activating material which acts as a promoter to the reaction, or in the presence actor. If the gas stream contains catalysts, it

passes together with the catalysts through the polymerization reactor. It has been 4found that on using polymerization and reforming catalysts of the adsorbent clay type, such as fullers earth or on usingbase catalysts like aluminum oxide, hydrochloric' acid gas or alkyl chlorides which react at the temperature reaction in the presence of these catalysts activate these catalysts. It has been found additionally, that these alkyl chlorides are themselves quite readily polymerized into higher molecular weight hydrocarbons or chlorinated hydrocarbons. While this polymerization is shown as occurring in a catalyzed reaction, the alkyl chloride with or without mixture with the hydrocarbon feed as here shown, may be polymerized in tubes 1 in an uncatalyzed reaction. The action in reactor 29 if desired may be catalytic or the end product of the uncatalyzed polymerization in 1 may be digested to aid polymerization in chamber 29 free of catalyst.

In carrying out the process shown in Figure 2 the feed is described as being made up of gasoline fractions to which may be added the alkyl chlorides. It is of course possible that the feed may be composed of alkyl chlorides alone. However, it is preferred to operate the process in Figure 2 whereby the alkyl chlorides are added to the gasoline and in the event the alkyl chlorides are used as a promoter in the catalytic polymerization reaction they will be added to the reaction mixture entering the polymerization zone. Heavy gasoline or-kerosene passes through line I, pump 2, to be passed with stock added `through valve 3 and pass then into line 4 and valve 3 into reforming coils 1 in furnace 8. Alkyl halides may be fed through line 60 and valveI 60a into reaction coil 1, or in the event that the feed is composed entirely of these halides, material is not introduced in line I. .If it is desired instead of feeding halides through line 60, valve 60a may be closed and the halides may be introduced into line 9. Polymerization catalyst is introduced into the stream passed into line 4 as previously described by any Well known solid feeding mechanism. The point of introduction should be prior to the introduction of the stream into coil 1 unless the catalyst is contained inside the coils. Reformed material passes through line 9. Before entering line 9 it meets liquid gas introduced through line I8. These liquid gases may be introducedy from stabilizer 46 as later described or may come from an extraneous source or may be both. The reactor 29 may be used through lines 23, pump 23a, heater 25 and line 21. Incompletely convertedgasoline is Withdrawn through line 36 and pump 31 to act as recycle stock as previously described. The re.

formed and polymer gasoline is withdrawn through line 38 into tank 39 and passed through pumpllll and heater 4I to stabilizer 46. The gases uncondensed by cooler 42 pass through line 43, compressor 43a into stabilizer 46. In stabilizer 46 the, gasoline and gases are separated into a stabilized, reformed and polymerized gasoline which is withdrawn through line 5I and cooler 53. Bottoms are circulated through line 41, heater 49 and line 58 to provide heat in the base of the column. Liquid fractions composed of butane, butylene, propane, propylene, ethane and ethylene are withdrawn in liquid form into tank 56 and passed to line 20 into-line 6I as will be hereinafter described. The uncondensed and fixed gases are withdrawn through line 54 controlled'by valve 55, cooled and condensed to provide a reux to column 46. The liquefied gases are withdrawn through line 20 to which may be added from an extraneous source, preferably unsaturated normally gaseous hydrocarbons or mixtures of said hydrocarbons and saturated no rmally gaseous hydrocarbons. 'Ihe gases may be separated in the following fashion: A `portion may be introduced through line I8 andvalve I8a as previously described. Another portion may be passed through line 6Iy controlled by valve 6Ia to the' reaction chamber 62 for conversion into the halide.

It has been found that unsaturated hydrocarence of activated fullers earth or aluminum oxide at temperatures from 32-39.0 F. to form alkyl halide. Propylene will add in the presence of hydrochloric acid at temperatures from 32-390 F. to hydrochloric acid very smoothly. The alkyl chloride thus formed may be introduced into the reaction stream by passing through line 63, valve 64 and line 65. In passing through 65 it passes as a vapor and may be introduced into line 9 to activate the polymerization in reactor 29. has been found that as much as from one-tenth to five-tenths percent of isopropyl chloride when added to the gases entering the. polymerizer reactor chamber 29 accelerates polymerization reaction markedly. The chloride may be passed via line 60 and valve Sainto coils 1. Instead of passinggthe isopropyl chloride as a gas the isoeither as an additional contact catalytic zone in Which case the catalyst is maintained in the retrolled by valve 3Ia directly into fractionator 33.

In fractionator 33 material is separated into a heavy residual fraction and is withdrawn through line 34. The bottoms are reheated by circulation propyl may be condensed by passing through line 63a, valve 64 remaining closed to cooler 66, co1- lector 61 and uncondensed gases may be removed through valved line 68; the condensatel is fed by pump 69 through valved line 1I] as previously described. The hydrochloric acid may be added into the stream entering the reactor 62 through line 1I In operating in the presence of isopropyl chloride, it would bel advisable to insure that the gases and liquid are moisture free. Provision will have to be made for separating free hydrochloric acid from the vapors in 54 and from the various condensates withdrawn fromthe system by treatment with sodium hydroxide.

The catalyst employed may be fullers earth or aluminum oxide, and preferably, the aluminum oxide formed by the co-precipitation of alumina and silica by the interaction of sodium silicate and aluminum sulfate, as previously described. Reaction chamber 62 is charged with activated fullers earth or aluminum oxide as` previously described. The temperature maintained in reactor 62 is as described, under 390 F. Dry hydrochloric acid gas is fed through 1I and alkyl chloride is introduced into line I9. The material entering line 4 is a slurry of the fullers earth or aluminum oxide and oil. The temperature maintained in reactor 1 is in the neighborhood of S30-1G20D F. and the temperature in reactor 29 is from S40-730 F. This temperature is maintained by the introduction of materiai through 2Il or through cooling the gases entering through 9 by an interchanger, as will be understood although not shown in the drawings, or by the control in the reactor 29 as shown in Figure 3. Cooling in line 9 may be provided as shown in Figures 3, 4 and 6. Pressure maintained in reactors 'I and 2e is in the neighborhood of 50G-1500 lbs.

Figure 3 shows schematically a combined process of reforming and polymerization process-in which separate reforming and polymerization zones are provided. A reforming zone is provided in coil 1 in which coil polymerization may also be effected if desired. Provision is made for the control of the temperature in the polymerization zone 29. The polymerization, being exothermic, the temperature in the reaction chamber 29 tends to rise, and it is desirable to control the temperature to prevent excessive increases in temperature.

Feed is introduced under pressure through line I and may pass 'either through line Ia and valve 2a or through line Ib and valve Ic, or through both to the reforming coils 1. It is preferred, in the event that the feed is a mixed feed containing a wide range of boiling fractions such as gasoline, kerosene and gas-oil, to rectify the feed by introducing it through line Ib and valve Ic into the fractionating chamber 33. In this chamber it meets the hot vapors from the reaction zones and aids in the fractionation of these vapors to form a heavy residual fraction 29 composed of the heavy ends of the charging stock and the heavy ends of the polymerized and reformed gasoline. A side cut of intermediate boiling fractions is removed through line I9b and circulated through line I9 to meet any portion of material by-passed through line Ia if any such is by-passed. If desired, a portion of the liquid gases which are to be polymerlzed are introduced through line 80 and the mixture is then passed through line Ia, heat exchange coil 3a, line 4 into the reforming coils 1 positioned in furnace 8. At the outlet of coil 1 the reformed gasoline is doused by contact with relatively cold heavy oil such as fuel oil entering through line I I and the partially cooled gases are then passed through heat exchanger 3b from stripping of the bottoms to insure the removal of Vtion of entrained materials and heavy ends of the vapors. Instead of passing the vapors through this chamber, the chamber may be bypassed by proper control of valve I0 in line 9 and valve 9a in line 9' to pass the vapors around the separator.- The vapors are then passed to the polymerizing zone 29. Instead of passing the gases through the reforming zone, or in addition to passing the gases through the reforming zone. they may be added to the vapor in line 9' through by-pass line It by proper control of valve Ia and valve 89a. The mixed gases and vapors are then passed through line 9' into the reaction zone 29.

In order to control the temperature in the reaction zone 29, the liquid gases may be expanded through spray BI by proper control of valves 82 and also by circulation of cooling uid through the cooler 83 via lines 93a and 8911. In operating the separator I2 in such manner that only the light fractions of gasoline are separated, the temperature of the outlet vapors may sometimes be below the desired temperature in the polymerization chamber 29. Thus for instance, the vapors issuing through line I5 may be in the neighborhood of 40o-450 F. while the reaction zone may be of a temperature of 600.F. and above. Under those circumstances it may be desirable to heat the reaction chamber 29 instead of cooling it. To do this the cooler 83 may be converted to a heater by circulating a heating fluid through the coils of the cooler 93. This cooler may be of the closed tube sheet type, the cooling iiuid circulating out of contact of material in the reaction chamber 29. The gases entering through valves 82 and spray 8| may be heated by passing through valves 84 and 88 and heater 85 by the propermanipulation of valve 81. Any desired proportion of the gases to be added for polymerization may be added in this way. Such gases thus added are not subject to the reactions occurring in the reforming coils 1. If it is desired to polymerize these gases without subjecting them to the reforming operation all the gases may be introduced in this manner.

-The heavy polymers formed in the reaction Zone and which are not volatile at the temperature in chamber 29 are withdrawn through 34a4 and the vapors are withdrawn through line 34 to be passed to fractionator 33. There they pass countercurrent to the feed Ib and the reiiux formed by cooling coils 42. In addition to the heavy cut I9b, a reformed and polymer gasoline is -withdrawn through the side out into tank 39 and passed by pump 4D through heater 4I into the stabilizer 46. The uncondensed vapors pass through line 43, compressor 43a into the stabilzer 46. In the stabilizer, the gasoline is separated into a stabilized gasoline, withdrawn through 5I and cooler 53. The bottoms are reboiled by circulation through line 41, heater 49 and return line 50. A liquid light hydrocarbon fraction withdrawn through line 56a into chamber 56 and composed of the fractions containing four or lower carbon atoms, both of the saturated and unsaturated types. Fixed gases are withdrawn through line 5I, condenser 54h and recycled as a reflux through line 54a. The liquid gas is circulated through line 2U by pump 51 and meets additional gases through valve 81 coming from storage 89. 'I'hese liquid gases are similar to those in 20 and are derived from other refinery sources. These gases may be sent through line 88 or 80 as previously described.

In operating the process according to this flow sheet the temperature i'n coil 1 may be from 600-1000 F. Thus, for instance, it may be operated at about 980 F., coold by the dousing me- The-reaction shown in Figure 2 may also be.,

carried out in Figure 3 in which case the reforming/catalysts may be fed as a slurry in line 4, separated in chamber I2, andthe polymerization catalyst be disposed as a contact catalyst mass in chamber 29. The temperatures and pressures discussed with relation to Figure 2 may be applied to the process of Figure 3.

The catalysts to`be used in the reforming operation may be either introduced into line Ia by a feederas previously described or may be positioned in the coils of reforming coils 1. 'Ihe relaction chamber 29 may be' charged with contact mass catalysts or the catalysts may be introduced into line 9to pass with the vapors throughline 9'. It is preferred, however, in the structure shown in FigureS, to charge reaction chamber 29 with catalysts.

In the operation according to the flow sheet shown in Figure 4, the polymerization and the reformingy operation are carried out in one zone. The feed which consists of kerosene and gasoline fractions containing added thereto propane, butane, propene. b utene, ethane, and ethylene produced as previously described, is passed under pressure together with the catalyst, if an entrained catalyst be used, through lines I and and through heater exchange 3a, line 4, coil 1 positioned in chamber 8. Instead of using an 'entrained catalyst I may use coils charged with catalytic mass.l Polymerized and reformed gasoline is then doused by contact with heavy fue] oil entering through II passed into the heat exchange 3b and through separator I2'. 'Ihe heavy fractions are withdrawn through line I3 and the vapors are passed through mist extractor and fractionator elements |2b and washed with oil' introduced through I 2a to separate-the heavy ends of 4the vapors. The vapors then pass through line I5 to the fractionator 33. in which the heavy oil is'withdrawn through line 28 and vapors refluxed by reflux produced by cooler 42. The polymer and reformed gasoline are 'withdrawn into side stream receiver 39, and passed by pump 40 through the heater 4I and introduced into Vthe stabilizer 46. The uncondensed vapors through line 43 are also introduced into stabilizer 40 by compressor 43a. In the stabilizer the vapors areseparated into a stabilized gasoline, withdrawn through 5| and cooler 53. The bottoms are heated by circulating through line 41, heater 49 and line 50. Reflux is obtained by the condensation of the vapors, withdrawn through by-pass 54, valve 55, condenser 54b and .condensate collectdin 54' returned 'through 54a as` a reflux. Liquid fraction withdrawn through 56a contains the hydrocarbonsranging from butanes and butylenes, propane and propylenes-to ethane and ethylene. 'Ihese are recirculated ,through line 20 to be sent to reformer coils 1.

The temperature chosen in Figure 4 in operating with fullers earth may be in the neighbon' hood of 840-1020" F.; the pressure in the neighborhood of 500-5000 lbs. The other conditions willfollow ure 3.

those described with regard to Fig-v In view of the fact that the polymerization reaction using certain catalysts as previously described, operates best at temperatures lower than the reforming operation, the form of heater shown in Figure 5 provides for reaction zones of alternately high and low temperatures in which the reaction mass is first passed through high temperature and then low temperature zones. The reforming catalysts may be positioned in the high temperature zone and polymerizing catalysts in the low temperature zone or the mixed catalysts may be used in both zones. The furnace 8 is dividedby vertical partition walls |00 to form chambers 8a and' 8b. The coils 1 are positioned in both zones, the flow being rst passed through the coils in zone 8a and then zone 8b, and then zone 8a, etc. as shown until the vapors exit. The furnace is heated by burner I 0I in combustion tunnel IOIa and the gases escape through con# duit- |02. The combustion gases may besplit by proper manipulation of dampers |03 and |04; A portion may be passed through conduit |05 pass-l ing into the flue |09 leading to the stack. Combustion air which is also used for cooling th'e chamber 8b is circulated through conduits IIO and III by fan II2 passed through low temperature zone 8b and conduit I I3. A portion of the thus preheated air is split by proper manipulation of dampers I I4 and I I5, and passes through conduit IIB to provide combustion air for burner IOI. In this fashion cold air, and if desired, flue gases recycled by the circulation of the portion of combustionA stream fromy conduit I 02, is circulated over the coils in chamber 8. Chamber 8b is therefore maintained .atconsiderably lower temperature from chamber V8a. Wall I 00 is preferably made of heat insulating materialwhich is chamber 8a to carry on the reforming reaction.`

and then passed through chamber 9b for polymerization. The gases after exiting from chamber 8b are then treated as shown in Figure 4. It will be lunderstood that the furnace construction and flow shown in Figure 5 may also be used in place of the furnaces shown in Figures 1, 2 and 3.

. In operating the reaction in Figure 5, theYcoils in chamber 8a shall be maintainedfrom 930- 1020 F. while the coils in chamber 8b shall be at` about G40-720 F. In this case the catalyst may be fullers earth or activated fullersvearth, or aluminum oxide, or the precipitated oxide pre-y viously described.

While the descriptions of the preferred operation in Figs. 4 and 5 are given with relation to catalyzed reactions,the process there described may also be carried out as an uncatalyzed reac-v tion by omitting the catalyst. In the case of Fig. 5 uncatalyzed operation, the temperature plane in zone 8a should be relatively higher in the range vof 1000-1300 F. and the temperature in zone 8b should be lower in the range of 'Z50-950 F.

Figure 6 showsa modication wherein the re forming and polymerization reaction is separated, and the polymerized andreformed materials are combined for treatment to-produce a blended,

stabilized, polymerized and reformed gasoline. Feed composed of petroleum fractions, for instance kerosene and gasoline, is introduced through line I, into fractionator 33. A sidecut having an intermediate boiling range is withdrawn through line Ia by. .pump 2 and sent through heat exchange 3a into reforming cham- V ber 1 positioned in furnace 8. Reformed gasoline is then contacted with the dousing oil composed of fuel oil introduced through I i, where it is partially cooled and then passed through heat exchange coil 3b. It meets in line 9 polymerized material introduced through line 90. The mixture of polylnerized and reformed gasoline passes.

into separator I 2 and through mist extractor I2b. 'I'he heavy ends are withdrawn through I3 and the uncondensed vapors of a temperature from 425-4501 F. are removed through line i5, then passed into the stripper and fractionator 33 where, by the aid of the feed I and the reboiler 33a and reilux coil 42 in fractionating chamber 33h, it is fractionated into heavy ends 28, recycle stock Ia and the side cut of reformed polymerized gasoline Withdrawn through line 39a. Reux is provided by coil 42. The uncondensed vapors are withdrawn through line 43. The side cut 39a is passed by pumpd into heater 6I and into the stabilizer 46. The uncondensed vapors are passed by pump 43a, line B3, into the stabilizer IIB. In this stabilizer the gasoline is stabilized by the aid of reboiler 46a and reflux provided by the condensation of gases withdrawn through valve 55, line 54 and 54a and condenser 54h. Stabilized gasoline is withdrawn through I, and liquefied gases containing the butanes, propanes, butylenes, propylenes, ethane and ethylenes pass through line 56a into collecting chamber 56 for recycling by pump 51 through line 20 into line 80. In this line it fmeets additional like materials through line 81. The commingled gases are then passed into heat exchanger 91a into polymerization coil 9| positioned in furnace 92. 'I'he hot gases are doused by mixing with a dousing medium such as gas oil, fuel oil. or kerosene, or gasoline introduced through 93 and passed through heat exchanger 9Ib and through S0 as previously described.

'Ihe reaction coil 1 may be uncatalyzed or catalyzed. If catalyzed, the catalyst may be any one of the reforming catalysts hereinabove indicated. The temperature may be regulated independently of coil 9|. The pressure in vcoil BI may be independently controlled by regulating valve 90a. The temperature in coil 1 may, depending upon the catalyst, be from 8501050 F. and the pressures from about 150-500 lbs. If uncatay understood from what has been said previously.

If the reactions in coil SI are uncatalyzed, the temperature may range from 850950 F.

The foregoing description of the several modifications of my invention described above are not to be considered aslimiting since many variations may be made within the scope of the following claims by those skilled in the art without departing from the spirit thereof.

The present application is a division of my c0- pending application, Serial No..35,'102, led August 12, 1935.

I claim:

1. A process for the production of reformed and polymer gasoline which comprises heating at a gasoline reformingtemperature in a series of coils in a restricted stream and without separation of vapors a slurry of comminuted catalyst and petroleum hydrocarbons having an end point not to exceed 650 F. and containing gasoline fractions and substantially completely reforming said gasoline fractions, separating the reformed gasoline from the heavier fractions to produce a vapor mixture of gasoline and lighter hydrocarbon fractions including the normally gaseous hvdrocarbons, subjecting said mixture to a polymerizing reaction apart from substantial quantities of materials having end points above 650 F. by maintaining said mixture at an elevated temperature for a period of time to cause polymerization of said normally gaseous hydrocarbons, and separating the mixture of polymer and reformed gasoline from said mixture.

2. A process for producing cracked and polymer gasoline which comprises passing a stream of vaporized petroleum stock through a cracking zone, carrying a finely divided catalyst in said stream of hydrocarbons from a point of introduction into said cracking zone to a. point remote from said point of introduction. subjecting said vapor in said cracking zone to temperature and pressures adapted to crack said petroleum stock, separating and removing said catalyst in a zone in which no substantial cracking occurs from vapors and gases, commingling said vapors and gases with a second catalyst adapted to polmnerize hydrocarbons of four and less carbon atoms contained in said vapors and gases and subjecting said mixture to pressures and temperatures adapted to polymerize said hydrocarbons of four and less carbon atoms and polymerizing said hydrocarbons in the presence of gasoline hydrocarbons formed by said rst mentioned cracking and separating cracked and polymer gasoline from said mixture of hydrocarbons.

3. A process for producing cracked and polymerized gasoline which comprises passing a stream of vaporized petroleum stock through a cracking zone into a polymerizing chamber and in said polymerizing chamber, .polymerizing gaseous hydrocarbons produced by said passage through said cracking zone and passing an oxygen-containing gas with said vapors passing through said cracking zone and polymerizing chamber to remove by reaction therewith diolenes and other gum-forming constituents from said vapors and gases.

4. A process for producing cracked and polymerized gasoline which comprises subjecting a vaporized petroleum stock to cracking reaction olenes and separating a cracked and polymer gasoline from said reaction products.

PHILIP SUBKOW. 

